Stress-free chemo-mechanical polishing agent for II-VI compound semiconductor single crystals and method of polishing

Abstract

In the present invention Stress-Free Chemo-Mechanical Polishing Agent For II-VI Compound Semiconductor Single Crystals And Method Of Polishing, a II-VI compound semiconductor single crystal wafer is polished smooth to within 50 angstroms by using a mixture of water, colloidal silica and bleach including sodium hypochlorite applied under time and pressure control to achieve chemo-mechanical polishing. Many such compound crystals are not susceptible to polishing by prior art methods.

What is claimed is: 
     
       1. A substantially stress-free chemo-mechanical polishing agent for Group II-VI compound crystal semiconductors, comprising in combination: a mixture of water, colloidal silica and sodium hypochlorite wherein the volume of silica is many times the volume of sodium hypochlorite.   
     
     
       2. The agent of claim 1, wherein: the volumetric ratio range for said mixture is as follows:   water 35-50   colloidal silica 10-35   bleach 1-5 including approximately 5.25% sodium hypochlorite.   
     
     
       3. The agent of claim 2, wherein: the semiconductor comprises mercury cadmium telluride and the preferred ratio by volume of the agent components is:   water (35)   colloidal silica (35)   bleach 5 including approximately 5.25% sodium hypochlorite and the rest inert materials.   
     
     
       4. A substantially stress-free chemo-mechanical polishing agent for Group II-VI compound semiconductor single crystal thin films capable of achieving surface smoothness of the thin film to less than fifty angstroms, comprising in combination: an aqueous solution of colloidal silica and sodium hypochlorite wherein the volume of silica is many times the volume of sodium hypochlorite.   
     
     
       5. The polishing agent of claim 4, wherein: the volumetric ratio range for said solution is:   water 35-50   colloidal silica 10-35   bleach 1-5 including about 5.25% sodium hypochlorite.